1. Field of Invention
The invention relates to a telephone apparatus and, more particularly, to a telephone apparatus that allows the use of a so-called call-waiting service, whereby when a third party attempts to call a first party while the first party is conducting a telephone conversation with a second party, the first party's telephone line connection can be switched between the second party's telephone apparatus and the to the third party's telephone apparatus.
2. Description of Related Art
Many conventional telephones have a catch-phone (or hereinafter, referred to call-waiting) device that, if there is a call from a third party to a first party while the first party is conducting a conversation with a second party, the first party receives a "beep" from the exchange carrier. The first party may then signal the exchange carrier to switch the first party's telephone line connection from the second party to the third party. The first party may then switch back to the second party by using the same call-waiting device to switch the line connection. Therefore, this type of telephone apparatus can substantially eliminate incidents where a caller is kept waiting due to a continual busy state of a called party's telephone.
However, this type of telephone needs to have a call-waiting operating portion (i.e., buttons, mechanisms, etc.) in addition to the conventional operating portions, thereby increasing the number of component parts, as well as the production costs of the telephone. In late-model telephones, the structure of the operating portion of the telephone have become rather complicated due to the adoption of additional dial buttons, such as "*", "#" and the like, and additional function buttons for, for example, abbreviated dialing (or speed dialing) whereby a telephone number pre-stored in a memory device, such as a non-volatile memory, is read out of memory and dialed. Therefore, a dedicated call-waiting operating portion may give rise to problems in installation space or external design.
In addition, Japanese Unexamined Patent Publication No. 07-32188 discloses a telephone that has a function whereby a first party operates a button that interrupts a call between a first party and a second party and simultaneously sends an "imitation holding sound" to the second party. However, the telephone only sends an "imitation holding sound" to the second party and does not perform a call-waiting-type function.